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Autonomously Finding Performance Regressions In The Linux Kernel

Last weekend a few Phoronix benchmarks were underway of the Linux 2.6.32-rc5 kernel when a very significant performance regression was spotted. This regression caused the PostgreSQL server to run at about 18% of the performance found in earlier kernel releases. Long story short, in tracking down this performance regression we have finally devised a way to autonomously locate performance regressions within the Linux kernel and potentially any Git-based project for that matter. Here are a few details.

Seemed to happen to me in rc4 as well. I use Gentoo, and I booted up one day and my /etc/profile.env got all messed up somehow. After fixing that from a livecd, I booted up again and ended up with a hole bunch of corruption, and lost a bunch of files. Pidgin preferences, /etc/portage/package.use, some KDE configuration stuff, etc. Oh and I lost my world file, so Portage forgot all the packages I had installed.

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Wait, this means that if I want to have consistent data on ext4 I must look at 5x slower PostgreSQL and other write-intensive applications? And proposed solution is either obscure mount switch with possibility of occasional file corruption or really _slow_ PostgreSQL. WTF?

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Wait, this means that if I want to have consistent data on ext4 I must look at 5x slower PostgreSQL and other write-intensive applications? And proposed solution is either obscure kernel switch with possibility of occasional file corruption or really _slow_ PostgreSQL. WTF?

I was thinking the same thing. I think I'll stick with Ext3 for now
(I have had Ext4 corruption before, so I simply don't trust the fs).